OLED is an Organic Light-Emitting Diode with characters of self-illuminating, high-brightness, wide viewing angle, high contrast, flexibility, and low energy consumption, so instead of traditional crystal display, this new generation display getting wide attention is applied widely in mobile screens, computer displays and full-color televisions. OLED display technologies, which is different from LCD display technologies, apply very thin organic material coating and glass substrate, and then these organic materials illuminate without backlight while current pass. However, due to organic material's easy reaction with hydrogen and oxygen, as being display equipment of organic material, the criteria of encapsulation of OLED display is very high. In order to cast commercial of OLED display, relative encapsulating technologies become research spotlight.
Common encapsulating technologies are curing glue frame from ultraviolet (UV) light, laser sealing of glass powder, face seal, dam and fill of glue frame and desiccant, film sealing and etc. Mention to dam and fill of glue frame and desiccant, how to make the desiccant dam on complete display without destroying the glue frame at the edge in the encapsulating technology to reach the best encapsulating effect is the direction researchers striving for. The most important point of filling the complete display with desiccant is good adhesion of desiccant spreadability on the interface of glass. The spreadability of liquid on interface is relative to the character of the interface. Polar liquid has better spreadability in a hydrophilic interface (smaller contact angle), but has worse spreadability in a hydrophobic interface (larger contact angle); in contrast, non-polar liquid has worse spreadability in hydrophilic interface, but better spreadability in hydropholic interface. After cleaning, an interface of common glass covers is a hydrophilic interface, thereby most liquid desiccant for usage is non-polar organics. Therefore, the spreadability of desiccant is worse in common situation, and causing uneven distribution of desiccant on production, fill incompletely in some portion, and even causing glue confliction situation because bobbles cannot be ejected on time due to uneven distribution of liquid desiccant when sudden attachment occurs.